The present invention pertains to a compressor assembly. More particularly the present invention pertains to a compressor assembly having a liquid-piston rotary compressor connected with its inlet port to a suction line and, with its outlet port, to a storage tank. An air-discharge line and a return line are connected to the storage tank and lead to the liquid-piston rotary compressor. The air-discharge line and return line recirculate operating liquid. A first after-cooler device, having a primary and a secondary zone, is connected with its primary circuit to the suction line and its secondary zone is connected to the air-discharge line. The condensate produced in the after-cooler device is recirculated as operating liquid.
A unit of this type is described in German Patent No. C-43 27 003. In this assembly, the outgoing air flowing out of the storage tank is fed to an after-cooler device, through which the intake air is also directed. Thus, a heat exchange takes place between the cooler intake air and the outgoing air warmed by the compression process, which results in a cooling of the outgoing air. This cooling causes a portion of the water vapor contained in the outgoing air to condense. The condensed water is recirculated into the operating liquid circulation circuit, so that the consumption of operating liquid is reduced. In spite of this reduction in the amount of operating liquid consumed, operating liquid still has to be added from time to time. It has been shown that designing the after-cooler device with larger dimensions does not substantially improve the efficiency of precipitating water vapor out of the outgoing air.
Therefore, an object of the present invention is to provide a compressor assembly of the type mentioned above so as to render possible a complete, or at least a nearly complete reduction in the consumption of operating liquid.